Cross flow Valve

(landing Gear System Component) An automatic flow-control valve installed between the gear-up and gear-down lines of the landing gear of some large airplanes. When the landing gear is released from its uplocks, its weight causes it to fall faster than the hydraulic system can supply fluid to the gear-down side of the actuation cylinder. The crossflow valve opens and directs fluid from the gear-up side into the gear-down side. This allows the gear to move down with a smooth motion.